1
|
Hoshino Y, Gaucher EA. Impact of steroid biosynthesis on the aerobic adaptation of eukaryotes. GEOBIOLOGY 2024; 22:e12612. [PMID: 38967402 DOI: 10.1111/gbi.12612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 06/20/2024] [Accepted: 06/24/2024] [Indexed: 07/06/2024]
Abstract
Steroids are indispensable components of the eukaryotic cellular membrane and the acquisition of steroid biosynthesis was a key factor that enabled the evolution of eukaryotes. The polycyclic carbon structures of steroids can be preserved in sedimentary rocks as chemical fossils for billions of years and thus provide invaluable clues to trace eukaryotic evolution from the distant past. Steroid biosynthesis consists of (1) the production of protosteroids and (2) the subsequent modifications toward "modern-type" steroids such as cholesterol and stigmasterol. While protosteroid biosynthesis requires only two genes for the cyclization of squalene, complete modification of protosteroids involves ~10 additional genes. Eukaryotes universally possess at least some of those additional genes and thus produce modern-type steroids as major final products. The geological biomarker records suggest a prolonged period of solely protosteroid production in the mid-Proterozoic before the advent of modern-type steroids in the Neoproterozoic. It has been proposed that mid-Proterozoic protosteroids were produced by hypothetical stem-group eukaryotes that presumably possessed genes only for protosteroid production, even though in modern environments protosteroid production as a final product is found exclusively in bacteria. The host identity of mid-Proterozoic steroid producers is crucial for understanding the early evolution of eukaryotes. In this perspective, we discuss how geological biomarker data and genetic data complement each other and potentially provide a more coherent scenario for the evolution of steroids and associated early eukaryotes. We further discuss the potential impacts that steroids had on the evolution of aerobic metabolism in eukaryotes, which may have been an important factor for the eventual ecological dominance of eukaryotes in many modern environments.
Collapse
Affiliation(s)
- Yosuke Hoshino
- GFZ German Research Centre for Geosciences, Potsdam, Germany
- Institute for Advanced Research, Nagoya University, Nagoya, Japan
- Synchrotron Radiation Research Center, Nagoya University, Nagoya, Japan
| | - Eric A Gaucher
- Department of Biology, Georgia State University, Atlanta, Georgia, USA
| |
Collapse
|
2
|
Cui L, Zhu K, Li R, Chang C, Wu L, Liu W, Fu D, Liu P, Qiu H, Tang G, Li Q, Gaines RR, Tao Y, Wang Y, Li J, Zhang X. The Cambrian microfossil Qingjiangonema reveals the co-evolution of sulfate-reducing bacteria and the oxygenation of Earth's surface. Sci Bull (Beijing) 2024; 69:1486-1494. [PMID: 38472019 DOI: 10.1016/j.scib.2024.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 12/25/2023] [Accepted: 12/26/2023] [Indexed: 03/14/2024]
Abstract
Sulfate reduction is an essential metabolism that maintains biogeochemical cycles in marine and terrestrial ecosystems. Sulfate reducers are exclusively prokaryotic, phylogenetically diverse, and may have evolved early in Earth's history. However, their origin is elusive and unequivocal fossils are lacking. Here we report a new microfossil, Qingjiangonema cambria, from ∼518-million-year-old black shales that yield the Qingjiang biota. Qingjiangonema is a long filamentous form comprising hundreds of cells filled by equimorphic and equidimensional pyrite microcrystals with a light sulfur isotope composition. Multiple lines of evidence indicate Qingjiangonema was a sulfate-reducing bacterium that exhibits similar patterns of cell organization to filamentous forms within the phylum Desulfobacterota, including the sulfate-reducing Desulfonema and sulfide-oxidizing cable bacteria. Phylogenomic analyses confirm separate, independent origins of multicellularity in Desulfonema and in cable bacteria. Molecular clock analyses infer that the Desulfobacterota, which encompass a majority of sulfate-reducing taxa, diverged ∼2.41 billion years ago during the Paleoproterozoic Great Oxygenation Event, while cable bacteria diverged ∼0.56 billion years ago during or immediately after the Neoproterozoic Oxygenation Event. Taken together, we interpret Qingjiangonema as a multicellular sulfate-reducing microfossil and propose that cable bacteria evolved from a multicellular filamentous sulfate-reducing ancestor. We infer that the diversification of the Desulfobacterota and the origin of cable bacteria may have been responses to oxygenation events in Earth's history.
Collapse
Affiliation(s)
- Linhao Cui
- State Key Laboratory of Continental Dynamics, Shaanxi Key Laboratory of Early Life and Environments, Department of Geology, Northwest University, Xi'an 710069, China
| | - Kelei Zhu
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
| | - Ruiyun Li
- State Key Laboratory of Continental Dynamics, Shaanxi Key Laboratory of Early Life and Environments, Department of Geology, Northwest University, Xi'an 710069, China
| | - Chao Chang
- State Key Laboratory of Continental Dynamics, Shaanxi Key Laboratory of Early Life and Environments, Department of Geology, Northwest University, Xi'an 710069, China
| | - Laiyuan Wu
- State Key Laboratory of Continental Dynamics, Shaanxi Key Laboratory of Early Life and Environments, Department of Geology, Northwest University, Xi'an 710069, China
| | - Wei Liu
- State Key Laboratory of Continental Dynamics, Shaanxi Key Laboratory of Early Life and Environments, Department of Geology, Northwest University, Xi'an 710069, China
| | - Dongjing Fu
- State Key Laboratory of Continental Dynamics, Shaanxi Key Laboratory of Early Life and Environments, Department of Geology, Northwest University, Xi'an 710069, China
| | - Peiyu Liu
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
| | - Hao Qiu
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
| | - Guoqiang Tang
- State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
| | - Qiuli Li
- State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
| | - Robert R Gaines
- Department of Geology, Pomona College, Claremont CA 91711, USA
| | - Yuxin Tao
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yinzhao Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
| | - Jinhua Li
- Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China.
| | - Xingliang Zhang
- State Key Laboratory of Continental Dynamics, Shaanxi Key Laboratory of Early Life and Environments, Department of Geology, Northwest University, Xi'an 710069, China.
| |
Collapse
|
3
|
Lyons TW, Tino CJ, Fournier GP, Anderson RE, Leavitt WD, Konhauser KO, Stüeken EE. Co-evolution of early Earth environments and microbial life. Nat Rev Microbiol 2024:10.1038/s41579-024-01044-y. [PMID: 38811839 DOI: 10.1038/s41579-024-01044-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/21/2024] [Indexed: 05/31/2024]
Abstract
Two records of Earth history capture the evolution of life and its co-evolving ecosystems with interpretable fidelity: the geobiological and geochemical traces preserved in rocks and the evolutionary histories captured within genomes. The earliest vestiges of life are recognized mostly in isotopic fingerprints of specific microbial metabolisms, whereas fossils and organic biomarkers become important later. Molecular biology provides lineages that can be overlayed on geologic and geochemical records of evolving life. All these data lie within a framework of biospheric evolution that is primarily characterized by the transition from an oxygen-poor to an oxygen-rich world. In this Review, we explore the history of microbial life on Earth and the degree to which it shaped, and was shaped by, fundamental transitions in the chemical properties of the oceans, continents and atmosphere. We examine the diversity and evolution of early metabolic processes, their couplings with biogeochemical cycles and their links to the oxygenation of the early biosphere. We discuss the distinction between the beginnings of metabolisms and their subsequent proliferation and their capacity to shape surface environments on a planetary scale. The evolution of microbial life and its ecological impacts directly mirror the Earth's chemical and physical evolution through cause-and-effect relationships.
Collapse
Affiliation(s)
- Timothy W Lyons
- Department of Earth and Planetary Sciences, University of California, Riverside, CA, USA.
- Virtual Planetary Laboratory, University of Washington, Seattle, WA, USA.
| | - Christopher J Tino
- Department of Earth and Planetary Sciences, University of California, Riverside, CA, USA.
| | - Gregory P Fournier
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Rika E Anderson
- Virtual Planetary Laboratory, University of Washington, Seattle, WA, USA
- Biology Department, Carleton College, Northfield, MN, USA
| | - William D Leavitt
- Department of Earth Sciences, Dartmouth College, Hanover, NH, USA
- Department of Chemistry, Dartmouth College, Hanover, NH, USA
| | - Kurt O Konhauser
- Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Eva E Stüeken
- Virtual Planetary Laboratory, University of Washington, Seattle, WA, USA
- School of Earth and Environmental Sciences, University of St Andrews, St Andrews, UK
| |
Collapse
|
4
|
Wei GY, Li G. Atmospheric oxygenation as a potential trigger for climate cooling. Sci Bull (Beijing) 2024:S2095-9273(24)00340-2. [PMID: 38902175 DOI: 10.1016/j.scib.2024.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 04/26/2024] [Accepted: 04/28/2024] [Indexed: 06/22/2024]
Abstract
Secular changes in atmospheric CO2 and consequent global climate variations, are commonly attributed to global outgassing and the efficiency of silicate weathering, which may have been linked to mountain formation, land/arc distribution, and plant colonization through geological time. Although oxidative weathering has been shown to exert a significant role in the propagation of weathering fronts through the oxidation of Fe-bearing minerals, the influence of atmospheric O2 concentration (pO2) on silicate weathering, CO2 consumption, and global climate has not been thoroughly evaluated. This study presents a numerical model aimed at estimating the effects of pO2 on the climate, considering the influence of pO2 on the regolith thickness and thus weathering duration of granitic domains. Our model simulations reveal that an increase in weathering efficiency, through deeper penetration of the oxidative weathering front in the granitic regolith, would independently introduce a steady-state climate cooling of up to ∼8 °C, in step with one-order of magnitude rise in pO2. This temperature change may have repeatedly initiated the runaway ice-albedo feedback, leading to global glacial events (e.g., Neoproterozoic Snowball Earth). Increasing granitic weathering efficiency caused by a substantial pO2 increase may also have contributed to the development of icehouse climate during the Phanerozoic.
Collapse
Affiliation(s)
- Guang-Yi Wei
- School of Earth Sciences and Engineering, and Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, Nanjing 210023, China
| | - Gaojun Li
- School of Earth Sciences and Engineering, and Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, Nanjing 210023, China.
| |
Collapse
|
5
|
Maloney KM, Halverson GP, Lechte M, Gibson TM, Bui TH, Schiffbauer JD, Laflamme M. The paleoredox context of early eukaryotic evolution: insights from the Tonian Mackenzie Mountains Supergroup, Canada. GEOBIOLOGY 2024; 22:e12598. [PMID: 38700417 DOI: 10.1111/gbi.12598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 03/18/2024] [Accepted: 03/27/2024] [Indexed: 05/05/2024]
Abstract
Tonian (ca. 1000-720 Ma) marine environments are hypothesised to have experienced major redox changes coinciding with the evolution and diversification of multicellular eukaryotes. In particular, the earliest Tonian stratigraphic record features the colonisation of benthic habitats by multicellular macroscopic algae, which would have been powerful ecosystem engineers that contributed to the oxygenation of the oceans and the reorganisation of biogeochemical cycles. However, the paleoredox context of this expansion of macroalgal habitats in Tonian nearshore marine environments remains uncertain due to limited well-preserved fossils and stratigraphy. As such, the interdependent relationship between early complex life and ocean redox state is unclear. An assemblage of macrofossils including the chlorophyte macroalga Archaeochaeta guncho was recently discovered in the lower Mackenzie Mountains Supergroup in Yukon (Canada), which archives marine sedimentation from ca. 950-775 Ma, permitting investigation into environmental evolution coincident with eukaryotic ecosystem evolution and expansion. Here we present multi-proxy geochemical data from the lower Mackenzie Mountains Supergroup to constrain the paleoredox environment within which these large benthic macroalgae thrived. Two transects show evidence for basin-wide anoxic (ferruginous) oceanic conditions (i.e., high FeHR/FeT, low Fepy/FeHR), with muted redox-sensitive trace metal enrichments and possible seasonal variability. However, the weathering of sulfide minerals in the studied samples may obscure geochemical signatures of euxinic conditions. These results suggest that macroalgae colonized shallow environments in an ocean that remained dominantly anoxic with limited evidence for oxygenation until ca. 850 Ma. Collectively, these geochemical results provide novel insights into the environmental conditions surrounding the evolution and expansion of benthic macroalgae and the eventual dominance of oxygenated oceanic conditions required for the later emergence of animals.
Collapse
Affiliation(s)
- Katie M Maloney
- Department of Earth and Planetary Sciences/GEOTOP, McGill University, Montréal, Québec, Canada
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Galen P Halverson
- Department of Earth and Planetary Sciences/GEOTOP, McGill University, Montréal, Québec, Canada
| | - Maxwell Lechte
- Department of Earth and Planetary Sciences/GEOTOP, McGill University, Montréal, Québec, Canada
| | - Timothy M Gibson
- Department of Earth and Planetary Sciences, Yale University, New Haven, Connecticut, USA
| | - Thi Hao Bui
- Department of Earth and Planetary Sciences/GEOTOP, McGill University, Montréal, Québec, Canada
| | - James D Schiffbauer
- Department of Geological Sciences, University of Missouri, Columbia, Missouri, USA
- X-ray Microanalysis Core, University of Missouri, Columbia, Missouri, USA
| | - Marc Laflamme
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, Ontario, Canada
| |
Collapse
|
6
|
Ben-Israel M, Holder RM, Nelson LL, Smith EF, Kylander-Clark ARC, Ryb U. Late Paleozoic oxygenation of marine environments supported by dolomite U-Pb dating. Nat Commun 2024; 15:2892. [PMID: 38570492 PMCID: PMC10991507 DOI: 10.1038/s41467-024-46660-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 03/04/2024] [Indexed: 04/05/2024] Open
Abstract
Understanding causal relationships between evolution and ocean oxygenation hinges on reliable reconstructions of marine oxygen levels, typically from redox-sensitive geochemical proxies. Here, we develop a proxy, using dolomite U-Pb geochronology, to reconstruct seawater U/Pb ratios. Dolomite samples consistently give U-Pb dates and initial 207Pb/206Pb ratios lower than expected from their stratigraphic ages. These observations are explained by resetting of the U-Pb system long after deposition; the magnitude of deviations from expected initial 207Pb/206Pb are a function of the redox-sensitive U/Pb ratios during deposition. Reconstructed initial U/Pb ratios increased notably in the late-Paleozoic, reflecting an increase in oxygenation of marine environments at that time. This timeline is consistent with documented shifts in some other redox proxies and supports evolution-driven mechanisms for the oxygenation of late-Paleozoic marine environments, as well as suggestions that early animals thrived in oceans that on long time scales were oxygen-limited compared to today.
Collapse
Affiliation(s)
- Michal Ben-Israel
- The The Fredy & Nadine Herrmann Institute of Earth Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
- Department of Life and Environmental Sciences, University of California, Merced, CA, USA
| | - Robert M Holder
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Lyle L Nelson
- Department of Earth Sciences, Carleton University, Ottawa, Ontario, ON, Canada
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, MA, USA
| | - Emily F Smith
- Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD, USA
| | | | - Uri Ryb
- The The Fredy & Nadine Herrmann Institute of Earth Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.
| |
Collapse
|
7
|
Xia Z, Li S, Hu Z, Bialik O, Chen T, Weldeghebriel MF, Fan Q, Fan J, Wang X, An S, Zhang F, Xu H, Chen J, Ji Z, Shen S, Lowenstein TK, Li W. The evolution of Earth's surficial Mg cycle over the past 2 billion years. SCIENCE ADVANCES 2024; 10:eadj5474. [PMID: 38427740 PMCID: PMC10906924 DOI: 10.1126/sciadv.adj5474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 01/26/2024] [Indexed: 03/03/2024]
Abstract
The surficial cycling of Mg is coupled with the global carbon cycle, a predominant control of Earth's climate. However, how Earth's surficial Mg cycle evolved with time has been elusive. Magnesium isotope signatures of seawater (δ26Mgsw) track the surficial Mg cycle, which could provide crucial information on the carbon cycle in Earth's history. Here, we present a reconstruction of δ26Mgsw evolution over the past 2 billion years using marine halite fluid inclusions and sedimentary dolostones. The data show that δ26Mgsw decreased, with fluctuations, by about 1.4‰ from the Paleoproterozoic to the present time. Mass balance calculations based on this δ26Mgsw record reveal a long-term decline in net dolostone burial (NDB) over the past 2 billion years, due to the decrease in dolomitization in the oceans and the increase in dolostone weathering on the continents. This underlines a previously underappreciated connection between the weathering-burial cycle of dolostone and the Earth's climate on geologic timescales.
Collapse
Affiliation(s)
- Zhiguang Xia
- State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, Jiangsu, China
- Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, Nanjing 210023, Jiangsu, China
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation & Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu 610059, China
- International Center for Sedimentary Geochemistry and Biogeochemistry Research, Chengdu University of Technology, Chengdu 610059, China
| | - Shilei Li
- Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, Nanjing 210023, Jiangsu, China
- Key Laboratory of Surficial Geochemistry, Ministry of Education, School of Earth Sciences, Nanjing University, Nanjing 210023, China
| | - Zhongya Hu
- State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, Jiangsu, China
- State Key Laboratory of Marine Geology, School of Ocean and Earth Science, Tongji University, Shanghai 200092, China
| | - Or Bialik
- Institute of Geology and Palaeontology, University of Muenster, Corrensstr. 24, 48149 Münster, Germany
| | - Tianyu Chen
- State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, Jiangsu, China
- Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Mebrahtu F. Weldeghebriel
- Department of Earth Sciences, Binghamton University, NY 13902, USA
- Department of Geosciences, Princeton University, NJ 08544, USA
| | - Qishun Fan
- Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Provincial Key Laboratory of Geology and Environment of Salt Lakes, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, China
| | - Junxuan Fan
- State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Xiangdong Wang
- State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Shichao An
- State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, Jiangsu, China
- Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Feifei Zhang
- State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Haoran Xu
- State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, Jiangsu, China
- Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Jiayang Chen
- State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, Jiangsu, China
- Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Zhihan Ji
- State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, Jiangsu, China
- Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Shuzhong Shen
- State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, Jiangsu, China
| | | | - Weiqiang Li
- State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, Jiangsu, China
- Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, Nanjing 210023, Jiangsu, China
| |
Collapse
|
8
|
Abstract
The origin of modern eukaryotes is one of the key transitions in life's history, and also one of the least understood. Although the fossil record provides the most direct view of this process, interpreting the fossils of early eukaryotes and eukaryote-grade organisms is not straightforward. We present two end-member models for the evolution of modern (i.e., crown) eukaryotes-one in which modern eukaryotes evolved early, and another in which they evolved late-and interpret key fossils within these frameworks, including where they might fit in eukaryote phylogeny and what they may tell us about the evolution of eukaryotic cell biology and ecology. Each model has different implications for understanding the rise of complex life on Earth, including different roles of Earth surface oxygenation, and makes different predictions that future paleontological studies can test.
Collapse
Affiliation(s)
- Susannah M Porter
- Department of Earth Science, University of California at Santa Barbara, Santa Barbara, California, USA;
| | - Leigh Anne Riedman
- Department of Earth Science, University of California at Santa Barbara, Santa Barbara, California, USA;
- Earth Research Institute, University of California at Santa Barbara, Santa Barbara, California, USA;
| |
Collapse
|
9
|
Ostrander CM, Bjerrum CJ, Ahm ASC, Stenger SR, Bergmann KD, El-Ghali MAK, Harthi AR, Aisri Z, Nielsen SG. Widespread seafloor anoxia during generation of the Ediacaran Shuram carbon isotope excursion. GEOBIOLOGY 2023; 21:556-570. [PMID: 37157927 DOI: 10.1111/gbi.12557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 04/13/2023] [Accepted: 04/25/2023] [Indexed: 05/10/2023]
Abstract
Reconstructing the oxygenation history of Earth's oceans during the Ediacaran period (635 to 539 million years ago) has been challenging, and this has led to a polarizing debate about the environmental conditions that played host to the rise of animals. One focal point of this debate is the largest negative inorganic C-isotope excursion recognized in the geologic record, the Shuram excursion, and whether this relic tracks the global-scale oxygenation of Earth's deep oceans. To help inform this debate, we conducted a detailed geochemical investigation of two siliciclastic-dominated successions from Oman deposited through the Shuram Formation. Iron speciation data from both successions indicate formation beneath an intermittently anoxic local water column. Authigenic thallium (Tl) isotopic compositions leached from both successions are indistinguishable from bulk upper continental crust (ε205 TlA ≈ -2) and, by analogy with modern equivalents, likely representative of the ancient seawater ε205 Tl value. A crustal seawater ε205 Tl value requires limited manganese (Mn) oxide burial on the ancient seafloor, and by extension widely distributed anoxic sediment porewaters. This inference is supported by muted redox-sensitive element enrichments (V, Mo, and U) and consistent with some combination of widespread (a) bottom water anoxia and (b) high sedimentary organic matter loading. Contrary to a classical hypothesis, our interpretations place the Shuram excursion, and any coeval animal evolutionary events, in a predominantly anoxic global ocean.
Collapse
Affiliation(s)
- Chadlin M Ostrander
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
- NIRVANA Laboratories, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
- Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah, USA
| | - Christian J Bjerrum
- Department of Geoscience and Natural Resource Management, Nordic Center for Earth Evolution, University of Copenhagen, Copenhagen K, Denmark
| | - Anne-Sofie C Ahm
- Department of Geoscience and Natural Resource Management, Nordic Center for Earth Evolution, University of Copenhagen, Copenhagen K, Denmark
- School of Earth and Ocean Sciences, University of Victoria, Victoria, British Columbia, Canada
| | - Simon R Stenger
- Department of Geoscience and Natural Resource Management, Nordic Center for Earth Evolution, University of Copenhagen, Copenhagen K, Denmark
- Norwegian Geotechnical Institute, Trondheim, Norway
| | - Kristin D Bergmann
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Mohamed A K El-Ghali
- Department of Earth Sciences and Earth Sciences Research Centre, Sultan Qaboos University, Muscat, Oman
| | | | | | - Sune G Nielsen
- NIRVANA Laboratories, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
- Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
| |
Collapse
|
10
|
Hesketh-Best PJ, Bosco-Santos A, Garcia SL, O’Beirne MD, Werne JP, Gilhooly WP, Silveira CB. Viruses of sulfur oxidizing phototrophs encode genes for pigment, carbon, and sulfur metabolisms. COMMUNICATIONS EARTH & ENVIRONMENT 2023; 4:126. [PMID: 38665202 PMCID: PMC11041744 DOI: 10.1038/s43247-023-00796-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 04/05/2023] [Indexed: 04/28/2024]
Abstract
Viral infections modulate bacterial metabolism and ecology. Here, we investigated the hypothesis that viruses influence the ecology of purple and green sulfur bacteria in anoxic and sulfidic lakes, analogs of euxinic oceans in the geologic past. By screening metagenomes from lake sediments and water column, in addition to publicly-available genomes of cultured purple and green sulfur bacteria, we identified almost 300 high and medium-quality viral genomes. Viruses carrying the gene psbA, encoding the small subunit of photosystem II protein D1, were ubiquitous, suggesting viral interference with the light reactions of sulfur oxidizing autotrophs. Viruses predicted to infect these autotrophs also encoded auxiliary metabolic genes for reductive sulfur assimilation as cysteine, pigment production, and carbon fixation. These observations show that viruses have the genomic potential to modulate the production of metabolic markers of phototrophic sulfur bacteria that are used to identify photic zone euxinia in the geologic past.
Collapse
Affiliation(s)
| | - Alice Bosco-Santos
- Institute of Earth Surface Dynamics, University of Lausanne, Lausanne, Switzerland
| | - Sofia L. Garcia
- Department of Biology, University of Miami, Coral Gables, FL USA
| | - Molly D. O’Beirne
- Department of Geology & Environmental Science, University of Pittsburgh, Pittsburgh, PA USA
| | - Josef P. Werne
- Department of Geology & Environmental Science, University of Pittsburgh, Pittsburgh, PA USA
| | - William P. Gilhooly
- Department of Earth Sciences, Indiana University-Purdue University Indianapolis, Indianapolis, IN USA
| | | |
Collapse
|
11
|
Stevenson DS. A New Ecological and Evolutionary Perspective on the Emergence of Oxygenic Photosynthesis. ASTROBIOLOGY 2023; 23:230-237. [PMID: 36413050 DOI: 10.1089/ast.2021.0165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
In this hypothesis article, we propose that the timing of the evolution of oxygenic photosynthesis and the diversification of cyanobacteria is firmly tied to the geological evolution of Earth in the Mesoarchean to Neoarchean. Specifically, the diversification of species capable of oxygenic photosynthesis is tied to the growth of subaerial (above sea-level/terrestrial) continental crust, which provided niches for their diversification. Moreover, we suggest that some formerly aerobic bacterial lineages evolved to become anoxygenic photosynthetic as a result of changes in selection following the reintroduction of ferruginous conditions in the oceans at 1.88 GYa. Both conclusions are fully compatible with phylogenetic evidence. The hypothesis carries with it a predictive component-at least for terrestrial organisms-that the development and expansion of photosynthesis species was dependent on the geological evolution of Earth.
Collapse
|
12
|
Reconstructing Earth's atmospheric oxygenation history using machine learning. Nat Commun 2022; 13:5862. [PMID: 36195593 PMCID: PMC9532422 DOI: 10.1038/s41467-022-33388-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 09/15/2022] [Indexed: 11/09/2022] Open
Abstract
Reconstructing historical atmospheric oxygen (O2) levels at finer temporal resolution is a top priority for exploring the evolution of life on Earth. This goal, however, is challenged by gaps in traditionally employed sediment-hosted geochemical proxy data. Here, we propose an independent strategy-machine learning with global mafic igneous geochemistry big data to explore atmospheric oxygenation over the last 4.0 billion years. We observe an overall two-step rise of atmospheric O2 similar to the published curves derived from independent sediment-hosted paleo-oxybarometers but with a more detailed fabric of O2 fluctuations superimposed. These additional, shorter-term fluctuations are also consistent with previous but less well-established suggestions of O2 variability. We conclude from this agreement that Earth's oxygenated atmosphere may therefore be at least partly a natural consequence of mantle cooling and specifically that evolving mantle melts collectively have helped modulate the balance of early O2 sources and sinks.
Collapse
|
13
|
Post-translational amino acid conversion in photosystem II as a possible origin of photosynthetic oxygen evolution. Nat Commun 2022; 13:4211. [PMID: 35864123 PMCID: PMC9304363 DOI: 10.1038/s41467-022-31931-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 07/08/2022] [Indexed: 12/18/2022] Open
Abstract
Photosynthetic oxygen evolution is performed at the Mn cluster in photosystem II (PSII). The advent of this reaction on ancient Earth changed its environment by generating an oxygenic atmosphere. However, how oxygen evolution originated during the PSII evolution remains unknown. Here, we characterize the site-directed mutants at the carboxylate ligands to the Mn cluster in cyanobacterial PSII. A His residue replaced for D1-D170 is found to be post-translationally converted to the original Asp to recover oxygen evolution. Gln/Asn residues in the mutants at D1-E189/D1-D342 are also converted to Glu/Asp, suggesting that amino-acid conversion is a common phenomenon at the ligand sites of the Mn cluster. We hypothesize that post-translational generation of carboxylate ligands in ancestral PSII could have led to the formation of a primitive form of the Mn cluster capable of partial water oxidation, which could have played a crucial role in the evolutionary process of photosynthetic oxygen evolution. How photosynthetic oxygen evolution is originated on ancient Earth is unknown. Here, the authors find that some amino acid residues at the ligand sites of the Mn cluster can be posttranslationally converted to the original carboxylate residues, which could have contributed to the evolutionary process of photosynthetic oxygen evolution.
Collapse
|
14
|
Boniolo M, Hossain MK, Chernev P, Suremann NF, Heizmann PA, Lyvik ASL, Beyer P, Haumann M, Huang P, Salhi N, Cheah MH, Shylin SI, Lundberg M, Thapper A, Messinger J. Water Oxidation by Pentapyridyl Base Metal Complexes? A Case Study. Inorg Chem 2022; 61:9104-9118. [PMID: 35658429 PMCID: PMC9214691 DOI: 10.1021/acs.inorgchem.2c00631] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
![]()
The design of molecular
water oxidation catalysts (WOCs) requires
a rational approach that considers the intermediate steps of the catalytic
cycle, including water binding, deprotonation, storage of oxidizing
equivalents, O–O bond formation, and O2 release.
We investigated several of these properties for a series of base metal
complexes (M = Mn, Fe, Co, Ni) bearing two variants of a pentapyridyl
ligand framework, of which some were reported previously to be active
WOCs. We found that only [Fe(Py5OMe)Cl]+ (Py5OMe = pyridine-2,6-diylbis[di-(pyridin-2-yl)methoxymethane])
showed an appreciable catalytic activity with a turnover number (TON)
= 130 in light-driven experiments using the [Ru(bpy)3]2+/S2O82– system at
pH 8.0, but that activity is demonstrated to arise from the rapid
degradation in the buffered solution leading to the formation of catalytically
active amorphous iron oxide/hydroxide (FeOOH), which subsequently
lost the catalytic activity by forming more extensive and structured
FeOOH species. The detailed analysis of the redox and water-binding
properties employing electrochemistry, X-ray absorption spectroscopy
(XAS), UV–vis spectroscopy, and density-functional theory (DFT)
showed that all complexes were able to undergo the MIII/MII oxidation, but none was able to yield a detectable
amount of a MIV state in our potential window (up to +2
V vs SHE). This inability was traced to (i) the preference for binding
Cl– or acetonitrile instead of water-derived species
in the apical position, which excludes redox leveling via proton coupled electron transfer, and (ii) the lack of sigma donor
ligands that would stabilize oxidation states beyond MIII. On that basis, design features for next-generation molecular WOCs
are suggested. We scrutinize the water oxidation
activity for pentapyridyl
metal complexes [MII(Py5R)Cl]+ (M = Mn, Fe,
Co, Ni; R = OH, OMe). Analysis of their stability, redox, and water-binding
properties shows that the complexes are not able to reach high-valent
intermediate states and do not catalyze water oxidation in their molecular
form.
Collapse
Affiliation(s)
- Manuel Boniolo
- Molecular Biomimetics, Department of Chemistry-Ångström Laboratory, Uppsala University, 75120 Uppsala, Sweden
| | - Md Kamal Hossain
- Synthetic Molecular Chemistry, Department of Chemistry-Ångström Laboratory, Uppsala University, 75120 Uppsala, Sweden
| | - Petko Chernev
- Molecular Biomimetics, Department of Chemistry-Ångström Laboratory, Uppsala University, 75120 Uppsala, Sweden
| | - Nina F Suremann
- Synthetic Molecular Chemistry, Department of Chemistry-Ångström Laboratory, Uppsala University, 75120 Uppsala, Sweden
| | - Philipp A Heizmann
- Synthetic Molecular Chemistry, Department of Chemistry-Ångström Laboratory, Uppsala University, 75120 Uppsala, Sweden
| | - Amanda S L Lyvik
- Molecular Biomimetics, Department of Chemistry-Ångström Laboratory, Uppsala University, 75120 Uppsala, Sweden
| | - Paul Beyer
- Physics Department, Freie Universität Berlin, 14195 Berlin, Germany
| | - Michael Haumann
- Physics Department, Freie Universität Berlin, 14195 Berlin, Germany
| | - Ping Huang
- Molecular Biomimetics, Department of Chemistry-Ångström Laboratory, Uppsala University, 75120 Uppsala, Sweden
| | - Nessima Salhi
- Molecular Biomimetics, Department of Chemistry-Ångström Laboratory, Uppsala University, 75120 Uppsala, Sweden
| | - Mun Hon Cheah
- Molecular Biomimetics, Department of Chemistry-Ångström Laboratory, Uppsala University, 75120 Uppsala, Sweden
| | - Sergii I Shylin
- Molecular Biomimetics, Department of Chemistry-Ångström Laboratory, Uppsala University, 75120 Uppsala, Sweden
| | - Marcus Lundberg
- Molecular Biomimetics, Department of Chemistry-Ångström Laboratory, Uppsala University, 75120 Uppsala, Sweden
| | - Anders Thapper
- Synthetic Molecular Chemistry, Department of Chemistry-Ångström Laboratory, Uppsala University, 75120 Uppsala, Sweden
| | - Johannes Messinger
- Molecular Biomimetics, Department of Chemistry-Ångström Laboratory, Uppsala University, 75120 Uppsala, Sweden.,Department of Chemistry, Chemical Biological Centre, Umeå University, 90187 Umeå, Sweden
| |
Collapse
|
15
|
Eukaryogenesis and oxygen in Earth history. Nat Ecol Evol 2022; 6:520-532. [PMID: 35449457 DOI: 10.1038/s41559-022-01733-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 03/15/2022] [Indexed: 02/07/2023]
Abstract
The endosymbiotic origin of mitochondria during eukaryogenesis has long been viewed as an adaptive response to the oxygenation of Earth's surface environment, presuming a fundamentally aerobic lifestyle for the free-living bacterial ancestors of mitochondria. This oxygen-centric view has been robustly challenged by recent advances in the Earth and life sciences. While the permanent oxygenation of the atmosphere above trace concentrations is now thought to have occurred 2.2 billion years ago, large parts of the deep ocean remained anoxic until less than 0.5 billion years ago. Neither fossils nor molecular clocks correlate the origin of mitochondria, or eukaryogenesis more broadly, to either of these planetary redox transitions. Instead, mitochondria-bearing eukaryotes are consistently dated to between these two oxygenation events, during an interval of pervasive deep-sea anoxia and variable surface-water oxygenation. The discovery and cultivation of the Asgard archaea has reinforced metabolic evidence that eukaryogenesis was initially mediated by syntrophic H2 exchange between an archaeal host and an α-proteobacterial symbiont living under anoxia. Together, these results temporally, spatially and metabolically decouple the earliest stages of eukaryogenesis from the oxygen content of the surface ocean and atmosphere. Rather than reflecting the ancestral metabolic state, obligate aerobiosis in eukaryotes is most probably derived, having only become globally widespread over the past 1 billion years as atmospheric oxygen approached modern levels.
Collapse
|
16
|
Eguchi J, Diamond CW, Lyons TW. Proterozoic supercontinent break-up as a driver for oxygenation events and subsequent carbon isotope excursions. PNAS NEXUS 2022; 1:pgac036. [PMID: 36713325 PMCID: PMC9802223 DOI: 10.1093/pnasnexus/pgac036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 03/04/2022] [Accepted: 03/28/2022] [Indexed: 02/01/2023]
Abstract
Oxygen and carbon are 2 elements critical for life on Earth. Earth's most dramatic oxygenation events and carbon isotope excursions (CIE) occurred during the Proterozoic, including the Paleoproterozoic Great Oxidation Event and the associated Lomagundi CIE, the Neoproterozoic Oxygenation event, and the Shuram negative CIE during the late Neoproterozoic. A specific pattern of a long-lived positive CIE followed by a negative CIE is observed in association with oxygenation events during the Paleo- and Neo-proterozoic. We present results from a carbon cycle model designed to couple the surface and interior cycling of carbon that reproduce this pattern. The model assumes organic carbon resides in the mantle longer than carbonate, leading to systematic temporal variations in the δ13C of volcanic CO2 emissions. When the model is perturbed by periods of enhanced continental weathering, increased amounts of carbonate and organic carbon are buried. Increased deposition of organic carbon allows O2 accumulation, while positive CIEs are driven by rapid release of subducted carbonate-derived CO2 at arcs. The subsequent negative CIEs are driven by the delayed release of organic C-derived CO2 at ocean islands. Our model reproduces the sequences observed in the Paleo- and Neo-proterozoic, that is oxygenation accompanied by a positive CIE followed by a negative CIE. Periods of enhanced weathering correspond temporally to supercontinent break-up, suggesting an important connection between global tectonics and the evolution of oxygen and carbon on Earth.
Collapse
Affiliation(s)
| | - Charles W Diamond
- Department of Earth and Planetary Sciences, University of California, Riverside, CA 92521, USA
| | - Timothy W Lyons
- Department of Earth and Planetary Sciences, University of California, Riverside, CA 92521, USA
| |
Collapse
|
17
|
Huang T, Wang R, Shen B. “中年地球”的磷循环与生物泵:再谈“沉寂的十亿年”. CHINESE SCIENCE BULLETIN-CHINESE 2022. [DOI: 10.1360/tb-2021-1168] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
18
|
Cooke GJ, Marsh DR, Walsh C, Black B, Lamarque JF. A revised lower estimate of ozone columns during Earth's oxygenated history. ROYAL SOCIETY OPEN SCIENCE 2022; 9:211165. [PMID: 35070343 PMCID: PMC8728182 DOI: 10.1098/rsos.211165] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 11/25/2021] [Indexed: 05/17/2023]
Abstract
The history of molecular oxygen (O2) in Earth's atmosphere is still debated; however, geological evidence supports at least two major episodes where O2 increased by an order of magnitude or more: the Great Oxidation Event (GOE) and the Neoproterozoic Oxidation Event. O2 concentrations have likely fluctuated (between 10-3 and 1.5 times the present atmospheric level) since the GOE ∼2.4 Gyr ago, resulting in a time-varying ozone (O3) layer. Using a three-dimensional chemistry-climate model, we simulate changes in O3 in Earth's atmosphere since the GOE and consider the implications for surface habitability, and glaciation during the Mesoproterozoic. We find lower O3 columns (reduced by up to 4.68 times for a given O2 level) compared to previous work; hence, higher fluxes of biologically harmful UV radiation would have reached the surface. Reduced O3 leads to enhanced tropospheric production of the hydroxyl radical (OH) which then substantially reduces the lifetime of methane (CH4). We show that a CH4 supported greenhouse effect during the Mesoproterozoic is highly unlikely. The reduced O3 columns we simulate have important implications for astrobiological and terrestrial habitability, demonstrating the relevance of three-dimensional chemistry-climate simulations when assessing paleoclimates and the habitability of faraway worlds.
Collapse
Affiliation(s)
- G. J. Cooke
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK
| | - D. R. Marsh
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK
- National Center for Atmospheric Research, Boulder, CO 80301, USA
| | - C. Walsh
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK
| | - B. Black
- Department of Earth and Planetary Sciences, Rutgers University, Piscataway, NJ, USA
- Department of Earth and Atmospheric Sciences, CUNY City College, New York, NY, USA
| | - J.-F. Lamarque
- National Center for Atmospheric Research, Boulder, CO 80301, USA
| |
Collapse
|
19
|
Xie S, Jiao N, Luo G, Li D, Wang P. Evolution of biotic carbon pumps in Earth history: Microbial roles as a carbon sink in oceans. CHINESE SCIENCE BULLETIN-CHINESE 2021. [DOI: 10.1360/tb-2021-0672] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
20
|
Rivera-Valentín EG, Filiberto J, Lynch KL, Mamajanov I, Lyons TW, Schulte M, Méndez A. Introduction-First Billion Years: Habitability. ASTROBIOLOGY 2021; 21:893-905. [PMID: 34406807 PMCID: PMC8403211 DOI: 10.1089/ast.2020.2314] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 12/22/2020] [Indexed: 06/13/2023]
Abstract
The physical processes active during the first billion years (FBY) of Earth's history, such as accretion, differentiation, and impact cratering, provide constraints on the initial conditions that were conducive to the formation and establishment of life on Earth. This motivated the Lunar and Planetary Institute's FBY topical initiative, which was a four-part conference series intended to look at each of these physical processes to study the basic structure and composition of our Solar System that was set during the FBY. The FBY Habitability conference, held in September 2019, was the last in this series and was intended to synthesize the initiative; specifically, to further our understanding of the origins of life, planetary and environmental habitability, and the search for life beyond Earth. The conference included discussions of planetary habitability and the potential emergence of life on bodies within our Solar System, as well as extrasolar systems by applying our knowledge of the Solar System's FBY, and in particular Earth's early history. To introduce this Special Collection, which resulted from work discussed at the conference, we provide a review of the main themes and a synopsis of the FBY Habitability conference.
Collapse
Affiliation(s)
| | - Justin Filiberto
- Lunar and Planetary Institute, Universities Space Research Association, Houston, Texas, USA
| | - Kennda L. Lynch
- Lunar and Planetary Institute, Universities Space Research Association, Houston, Texas, USA
| | - Irena Mamajanov
- Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo, Japan
| | - Timothy W. Lyons
- Department of Earth and Planetary Sciences, University of California Riverside, Riverside, California, USA
| | - Mitch Schulte
- Planetary Science Division, NASA Headquarters, Washington, District of Columbia, USA
| | - Abel Méndez
- Planetary Habitability Laboratory, University of Puerto Rico Arecibo, Arecibo, Puerto Rico
| |
Collapse
|